Resinous condensation products and process of making the same.



. a specification.

UNITED STATES PATENT OFFICE.

wrnmnm'c. Assam,

RESINOTIS CONDENSATION PRODUCTS AND PROCESS OF-MAKING THE SAME.

To all whom'it may concern:

Be it known that I,WILL1AM C. ARSEM, a citizen of the United States,residing at Schenectady, in the county of Schenectady, State of NewYork, have invented certain new and useful Improvements in ResinousCondensationProducts and the Process of Making the Same, of which thefollowing is This applicatlon is a continuation in part of myapplication filed September '12,- 1912, Serial No. 719,994..

1 The present invention relates to synthetic resinous compositions whichmay be rendered insoluble and infusible, and which are 7 suitable forthe production of molded ar- 1- am-molecule 0 "rep aced by oleic acid.Oleic acid being a;

ticles, electrical insulation, varnishes, etc.

Glycerol, and other polyhydric alcohols, combine with various'polybasicacids at an elevated temperature to form resins. These resins apparentlyare esters of complex molecular structure. Two or more molecules oforganic base or alcohol may combine with two or more molecules of acid,the molecular structure probably varying with the proportions and theconditlons. Unless special precautions are taken, it is likely that amixture of various esters such as mono,'di, or tri-acid esters, neutralesters, and perhaps other compounds are formed during the reaction. Inaccordance with my present invention esters are formed from a polyhydricalcohol and a polybasic acid in such proportions that free orunesterified hydroxyl groups remain, and such esters 'are then combinedwith oleic acid to complete the esterification, thus producing mixedesters of fairly definite composition having properties-which renderthem especially valuable for electrical insulations.

An ester of a polyhydric alcohol, as, for example, glycerol, and apolybasic acid, as, for example, phthalic acid, or its anhydrid, isfirst prepared, these two ingredients being used in such proportionsthat unesteri- -fied hydroxyl groups remain.

' As has already been indicated, 11} grammolecules ofphthalic anhydridwill combine with 1 gram-molecule of glycerin. In the preparation of'thepreferred form of resin phthalic anhydrid is monobasic acidgram-molecule of the same is required to replace i gram-molecule ofSpecification of'Letters Patent.

Application filed July 25, 1913. Serial No. 781,111.

. Patented June 2, 1914.

the-dibasic phthalic anhydrid. Instead of combining with the glycerinall of. the phthalic anhydrid to'loe added, I refer to .,combine 1gram-molecule'of glycerln withl' gram-molecule of phthalic anhydrid andthen to add the rest of the phthalic anhyor' sonmmc'rnnr', NEW YORK,nss'renon T0 GENERAL ELECTRIC;

comrm, A CORPORATION on NEW YORK.

drid with the oleic acid. For example, 92

parts of glycerin are mixed with 148 parts by weight of phthalicanhydrid These materials are gently heated, the tempera ture beinggradually increased to 200 C. .At this temperature reaction takes place.with the evolution of gas and the mass should be kept at a temperatureof about 20O to 210 C. until evolution of gases tends to decrease, carebeing taken'to prevent undue rise of temperature. The reaction should bestopped before the mass becomes viscous and atty which is an indicationthat the reaction has proceeded too far.

The mixture of oleic acid and phthalic anhydrid is then added tocompletely esterify theremaining uncombined hydroxyl groups of themono-acid ester. In the present example, this will require a mixture byweight with 141 parts of oleic acid and 37 parts of phthalic anhydrid.An excess of oleic acid is not recommended when the material it to beused for' electrical insulating purposes, but in some cases may beadvantageous as it tends to make the product more flexible. When theoleic acid mixture is first added it forms an immiscible layer with thesaturated resin but after heating from 200 to 215 C. reaction occurs;The material becomes a deep red color and the temperature may 'then beraised from 220 to 230 C. At this temperature the reaction isaccompanied with considerable frothing,

flexibility may be varied by varying the pro portions of the phthalicand oleic acids. Decreasing the amount of oleic acid decreases theflexibility of the resin.

The resin in its final hardened state is surfaces for insulating orother industrial purposes. In some cases when the material is to be usedfor impregnatlng purposes 1t is desirable to first partially harden itby' heating to a temperature of about 150 to 160 C. for some length oftime up to about 15 hours, which removes uncombined constituents andeliminates water. The material thus treated may then be dissolved orotherwise utilized. The hardening is completed by heating the varnishedsurface after evaporation of the solvent. The resinous material may alsobe used in the production of molded compounds and for this purpose maybe mixed either in the liquid or dissolved state or as a dry powder witha filler such'as asbestos, clay, ground slate, silica, and the like, andmolded under pressure, or it may be molded without any inert admixture,part at least of the material being in the state of a powder.

The change in physical properties due to the hardening heat treatment isnot entirely 3-..A flexible, fusible, soluble resinous product of apolyhydric alcohol, phthalic anhydrid, and oleic acid, said materialbeing convertible by heating to an insoluble,

in u

sible state, while retaining flexibility. 4E. The process which consistsin heating a mixture of glycerol and phthalic anhydrid in about equalmolecular proportions by weight until combination takes place, thenadding one-fourth molecular proportion of phthalic anhydrid and one-halfmolecular proportion of oleic acid by weight, and completing thereaction to form a fusible, soluble resin.

In witness whereof, I have hereunto set my hand this 24th day of July,1913.

WILLIAM G. ARSEM.

Witnesses BENJAMIN B. HULL, HELEN ORFORD.

